1. Field of the Invention
The present invention relates to an X-ray analyzer and an X-ray analysis method for performing fluorescent X-ray analysis and the like of a sample surface.
2. Description of the Related Art
In fluorescent X-ray analysis, an X-ray emitted from an X-ray source is irradiated onto a sample, a fluorescent X-ray which is a characteristic X-ray emitted from the sample is detected by an X-ray detector, and a spectrum is acquired from the energy and a qualitative analysis or quantitative analysis of the sample is performed. Fluorescent X-ray analysis is widely used in process management, quality management, and the like since a sample is quickly analyzed without being broken. In recent years, as measurement of small amounts becomes possible due to improvements in precision and sensitivity, fluorescent X-ray analysis is expected to be widely used particularly as an analysis method of detecting harmful substances included in a material, a composite electronic component, and the like.
In the related art, for example, in JP-A-2007-292476 (Claims, FIG. 1), a composite apparatus having a revolver which enables free switching between an objective lens of an optical microscope and an X-ray generator of an X-ray analyzer on the same optical axis is suggested. In the composite apparatus, it is not necessary to move a sample to an analysis position detected by the optical microscope and then align the position to be analyzed according to the movement, as the X-ray analysis can be performed by irradiating a primary X-ray from the X-ray generator under conditions in which the same sample position is maintained. Moreover, in the composite apparatus, the sample is observed while changing the magnification of the objective lens by the revolver, and alignment in the z direction is set beforehand such that the focal position of the objective lens and the focal position of the primary X-ray match each other.
The following problems remain in the known technique described above.
In the known X-ray analyzer, the sample is observed using the optical microscope in order to specify and designate a measurement point first. However, when performing quantitative analysis and the like, it is necessary to measure the distance between the specified measurement position (irradiation point) and the X-ray optical system, such as the X-ray source, with high precision. In the technique disclosed in JP-A-2007-292476, a configuration measuring the distance up to the measurement position is not adopted since the focal position of the objective lens and the focal position of the primary X-ray are set beforehand to match each other. Furthermore, in this technique, an optical system, such as a mirror, is used to dispose the optical microscope and the X-ray optical system on the same axis, but an optical microscope with a large field of view is preferable for specifying the measurement position. In this case, an optical system, such as a large mirror, is needed. However, since a large space for the mirror is required in this case, the distance between the X-ray source and the sample is increased. As a result, it is difficult to obtain high sensitivity.
Furthermore, an example of a method of measuring the distance between the measurement position and the X-ray optical system, such as the X-ray source, by the optical microscope includes a method of measuring the distance by the focal distance of the optical microscope. In the case of this method, particularly when designating a measurement position for an uneven sample, high operability is obtained as the depth of field increases. However, when measuring the distance from the measurement position, a small depth of field is preferable in order to measure the distance with high precision. For this reason, when performing distance measurement using an optical microscope which specifies the measurement position, there is a problem that the precision of the distance measurement is low because the depth of field was large.